I'm hunting ideas. My obs is now complete and while the roof is heavy, it is on multiple rollers and can be moved manually; but I am looking for a winch and capstain or similar system to do it instead. I wonder if any of the many new obs builderes or the old hands have any interestiung suggestions.
Even a 12volt cheap winch like the ones sold by 4WD accessories shops
Supercheap has them in their cat&dog $119. You could also access one of the chain driven Panel lift door openers, they would work very nicely and they have limit switches and jam detection as well as remote control. Here's one on Ebay up for auction.
Last edited by acropolite; 10-01-2009 at 02:35 PM.
The reason I ask is because there are good ones and bad ones. The good are very good and the bad are a nightmare, I know this from experience I service/ install garage doors for a living.
Peter, If you have a heavy roof forget the bunnings panel motors, they aren't up to the load.
I have used panel motors successfully for 2 rooves and they work well.
Another more expensive option is gate motors like the observatory I automated here http://www.gco.org.au/skylive/index.htm (scroll down to middle observatory). There are a lot more heavy duty and are not resticted to travel length like panel door motors, which is around 3m throw before you get into industrial motors (read expensive).
There are a few gate motors I can recommend to you, and a few panel motors I can recommend, and they aint the same brand!
Brett : I work for Gliderol Garage Doors here in Brisbane, and our doors use Gliderol branded motors... however I think the are made by GTS motor systems... I can find out more on monday...
Our installers never have complaints about our panel door motors, and we very very rarely have motors come back to us under warranty.. I dare say they are of good quality (I have one installed in my house... Have had for the past 4 years (and 6 years before I move here) and apart from general services including the oiling and greasing of certain parts its never faultered once..
The gliderol motors are light duty, and the have a plastic body that tends to flex under load and then you get gear slippage. The control boards can be a little sensitive too. One thing that is very handy about the gliderol control board is they have a seperate open, close, and rotation command (1 push for open, close,stop.), most operators have only the rotation command. The seperate open and close commands are very desirable for observatory control.
I guess they would be suitable for a very small roof, but not the size of ten peaks observatory.
That said there are worse motors out there.... but there are better also.
I should give an indication of the size f the beast. Pics attached. It's a 5 x 4 metre construct in streel. I suppose a centre-pull would be OK. I was wondering if I would need to pull from both sides to avoid slewing and the like. But from the middle should be fine.
Alex, do you thing the motor you mentioned could deal with this weight?
It uses an electric wheelchair motor/gearbox as is, with a built in dog clutch to release the gearbox for manual pushing.
The 24v DC motor easy to power. In this case 12v 5A was all that was required, and still had enough power to pull the roof right off the walls. At 24v 20A it would pull the OBs out of the ground .
Roll ON is cool, because you can image all night whilst sleeping, and set a timer for autoclose (and in my case rain. One drop and its done.)
Ive used it for 2 years without a problem. Its closed several times on rain correctly, on the 1st drop.
A S/H motor gearbox from a wheelchair dealer or ebay would be cheap, say $50, or buy a junk whole chair for a $100 and you have 2 motors and 2 usable dryfit batteries .
The pull on is centered and I get no skew at all.
To also pull off is trickier, perhaps pullys then to allow 2 ropes, one down iether side along the walls, but still just wind up rope on a capstan.
Basically, I used an electric wheelchair motor/gearbox , because its cheap, vastly underpowered (so its very reliable), ready to go as is and easy to power and speed contol, if required.
Sorry not meaning to hijack Peter's thread; but that is very impressive Fred. How does the one drop of water get the motor to trigger? Would it close just with a bit of dew also, which may be a bit too sensitive?
Sorry not meaning to hijack Peter's thread; but that is very impressive Fred. How does the one drop of water get the motor to trigger? Would it close just with a bit of dew also, which may be a bit too sensitive? .
Yeah, I didnt mean to get off Peters question too much, but motorised roll on/off is the perfect opportunity for auto close, the definitive answer to megadata .
I posted this project a couple of years ago, so sorry about the repeat. The rain sensor is vero board with alternate strips connected in parallel connected to a comparator (well, in short a relay), so one drop shorts the tracks and closes the relay which just shorts the manual close switch.
Dew doesnt affect it, there is a power resistor glued to the bottom of the veroboard to keep it slightly warm and dry.
OK, to build the rain sensor takes some electronics knowledge but was only about $20 all up in parts. I also have an alarm next to my bed just in case. A power loss anywhere in the Obs also triggers close, and if the roll off power goes altogether, the battery powered alarm goes off too.
The rain sensor is not essential, but nice, and it could be done in different ways.
I like it Fred.[/quote]
Quote:
Originally Posted by acropolite
Looks good Fred, I notice you've used a smart relay, that would add to the cost somewhat.
Yes, its about $240, but again not essential. Youd have to know how to program it, but I can give the program to anyone who wants it .
Manual open/close buttons would be fine (with 2 latching relays, $5 each), with the roof closed limit switch just tripping the close relay off, and a seperate simple clock to start close (not required really, just get up in the morning and manually close, on a typical imaging night, imaging can go to 3-5am anyway). BTW close also turns off the 12v supply to the cam, dew heaters and mount. Although the video shows a mount tracking limit switch to trigger close, I dont use it now, I set the mount saftey limit to the same place and it just stops tracking.
The smart relay allowed total control ie monitoring the limit switches and timing everything in case of a jamb up/broken switch and trigger the alarm, all nice and fun to make extras, but not essenttial, the roof has never jambed.
Alexs Gliderol motor will not run your roof successfully. They simply arent stong enough or have enough throw to open completely.
If you are going to use a panel door motor use one of these http://chamberlainanz.rtrk.com.au/?s...535&kw=1049565 scroll down to 230t, they are almost indestuctable, unrefined and hugely overpowered. In the industry they are know as the tractor, they use a 240v motor instead of low volt dc like most motors now utilize. I have installed around 3-400 of these and I have never had a powertrain failure. That says a lot. They also come with a extension kit to run upto 4m throw. I use a lot of different motors froma lot of different companies, so I guess I'm trying to say I'm not biased toward a single brand.
I dont use them anymore due to the low frequency hum (ac motor) and lack of features and no soft start. I actually use the mt60 and mt1000 dc motors for my garage door installs, but for your situation the 230t is THE best motor to use.
If you want the controllability mentioned by bassnut use on of these http://www.ata-aust.com.au/shop/?fus...o&ct_id=97&i=5 go down to the 24v model slider. This is the almost the same motor that I used at the gco web site I linked to earlier. This features seperate inputs so you dont have to setup relays/megadata and stuff, Its all built in to the control board. And it has so many features that are SOOOOO handy for an observatory(gco's system shuts automatically on rain, wind over a threshold, internet loss. It is completely internet controlled). The ata gate motors are reliable too, although their warranty service leaves a little to be desired.